Support FAQ

FAQ

Configuring Serial Port Connections with SSH

If you use generic SSH utilities such as PuTTY or SSHTerm to access an Opengear console server serial port, an SSH tunnel is set up connecting to the port using standard port addresses IP Address _ Port (3000 + serial port #) i.e. 3001 – 3048. If you then run the client again to access a second port then a second SSH tunnel will be set up. However when SDTConnector is used to access the console server serial port then only the one SSH tunnel is set up to the console server and connections to multiple ports (and hosts) can then be set up through that one SSH port. This can be important as there is a limit on the number of concurrent SSH sessions (SDT tunnels) that can be open at the one time (50 for CM41xx, IM42xx or IMG console servers and 10 for CM/SD4001/8 console severs).

Also with 2.0.9 firmware (or later) users can use the standard SSH port 22 and establish connections to any of the serial ports on their Opengear console server.

With SSH connections that are configured using the standard SSH port 22, the serial port being accessed is identified by appending a descriptor to the username. This syntax supports any of:
[username]:[portXX]
[username]:[port label]
[username]:[ttySX]
[username]:[serial]

So for a user named 'fred' to access serial port 2, when setting up the SSHTerm or the PuTTY SSH client, instead of typing username = fred and ssh port = 3002, the alternate is to type username = fred:port02 or (username = fred:ttyS1) and ssh port = 22. Alternately, by typing username= fred:serial and ssh port = 22, the user is presented with a port selection option:

SSHtunneling

It is recommended that users always use SSH as the security protocol when connecting to the console or secure device server over the Internet or any other public network. With this new syntax, users can now set up SSH tunneled connections to all serial ports with only a single IP port 22 having to be opened in their firewall/gateway. Similarly when using SDT the user can set up any number of VNC, RDP, telnet and HTTP network connections to be forwarded over the LAN through the one open SSH port 22.